What is the radius of a normal cylinder whose height is 21 cm and curved surface area is 1386 cm2?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 10.5 cm
Formula used
Curved surface area (CSA) of cylinder = 2πrh
where, r = the radius of the cylinder
h = the height of the cylinder
Calculation
⇒ 2πrh = 1386
⇒ 2 * (22/7) * r * 21 = 1386
⇒ r = 63/6 = 10.5 cm